Not genius, but still good

The most startling shot in Paranormal Activity 3 is something even the film’s determined unbelievers would concede to be damnably effective.

Suburban San Diego three-story home, 1988, in the middle of the VHS tape era. A homemade surveillance camera attached to an oscillating floor fan scans left, then right, and we see a mother (Lauren Bittner) of two girls (Chloe Csengery and Jessica Tyler Brown) walk out of the kitchen.

She is alone. The kitchen seems to be its usual self, each appliance and bowl and fork and spoon in its place.

A few seconds later she re-enters the same kitchen just as the video camera pivots to reveal that everything has disappeared. And then … Modest, low-fi horror continues to find a friend in the cheapo but very shrewd Paranormal Activity franchise, which consists now of three films designed for single-use, one-time consumption. But you know what? They work. Like its predecessors, the new “found footage” lark builds tension and dread slowly and sticks it to you just when you need something to happen.

Like the whining dolts in The Blair Witch Project, the key character with the camera, a wedding videographer played by Christopher Nicholas Smith, finds reasons to film all his own worst experiences with the supernatural and the paranormal and the oogly-boogly. It’s a ridiculous conceit getting slightly more ridiculous by the film. But I have been entertainingly spooked by the results each time. And since these films played a significant role in killing off (for now) their aesthetic opposite, the vicious-spirited and dreary Saw franchise, it’s hard not to feel warmly toward the little ghost stories that could.

In this prequel, we get to know “Toby,” the unseen demonic frenemy of preteen daughter Kristi (Brown). The cross-cutting between three surveillance camera set-ups in Paranormal Activity 3 — one near the kitchen, one in the girls’ bedroom upstairs, one in the adults’ bedroom — is more aggressive than the rhythms in the first two. The directors Henry Joost and Ariel Schulman made the recent mystery-documentary Catfish, and their weaselly fake-naturalism proves a fine fit for this project.

At Wednesday’s screening, there was no reminder or interest in getting the audience members to turn off the cellphones. Tweeting about the movie during the movie was, in fact, encouraged. Paramount’s social-media marketing strategy for the Paranormal flicks has been a work of genius. The films are not works of genius. They are, however, wily reminders of the virtues of restraint when you’re out for a scare.